This proposal is concerned with the total synthesis of compactin, a potent competitive inhibitor of HMG-CoA reductase (Ki equals 1nM) using a combination of chemical and microbiological methods. Optically-active bifunctional C4 and C5 intermediates, which are important building blocks for organic compounds possessing chiral secondary and tertiary centers, will be prepared by microbial oxidation of aromatic substrates possessing enantiotopic methyl groups. Attempts will be made to develop methods for the preparation of chiral allylic alcohols utilizing microbial alcohol deydrogenases.